1. Field of the Invention
The present invention relates to a display device having a power saving feature which controls power consumption in accordance with conditions.
2. Description of the Background Art
At the present time, almost all display devices such as liquid crystal displays used with connection to computer devices have a power saving feature compliant with the DPMS (Display Power Management Signaling) standard established by VESA (Video Electronics Standards Association) which is an organization for standardization of standards of graphic equipment associated with computer devices.
The DPMS is a standard relating to the power management of display devices. A DPMS-compliant device automatically makes a transition to a power saving mode from a normal mode and a transition to the normal mode from the power saving mode in accordance with the conditions of a computer device connected thereto.
The term “normal mode” refers to an operating state in which text, graphics and the like are displayed in a user-recognizable manner in response to signals supplied from the computer device by using supplied electric power. The term “power saving mode,” on the other hand, refers to an operating state in which power consumption of the display device is reduced by not using supplied electric power (or by reducing the use of the supplied electric power).
The switching between the normal mode and the power saving mode is controlled based on the judgment of the display device as to whether there are signals supplied from the computer device or not.
Concretely, the display device identifies the type of synchronization signals supplied (or not supplied) from the computer device to the display device among horizontal and vertical synchronization signals, and performs the switching between the normal mode and the power saving mode based on the DPMS standard in response to the identified synchronization signal (see the URL http://www.vesa.org).